Standard chemical approaches to metal nanoparticle synthesis are energy intensive and generate significant quantities of hazardous waste, making nanoparticles much more expensive than the metals from which they are formed. Development of mechanical methods that produce metal nanoparticles directly from bulk material would bypass high energy and potentially toxic chemical intermediates and allow for maximum atom efficiency. High-energy milling and cryomilling can produce metal nanoparticles from micro-particles, however the nanomaterials often suffer from poor crystallinity, incorporation of impurities, and a lack of size and shape uniformity. See N. Kumar et al., RSC Advances 6, 111380 (2016). More success has been achieved by passing metals through the gas phase; for example, direct evaporation of metals onto a surface can create very small quantities of nanoparticles. Larger amounts can be produced by constantly refreshing a surface or evaporating the metal under a liquid, as in laser ablation. See A. De Bonis et al., J. Phys. D: Appl. Phys. 46, 445301 (2013); and S. Stoeva et al., J. Am. Chem. Soc. 124, 2305 (2002). So, while these few methods do exist for the mechanical formation of metal nanoparticles, they are typically energy intensive, difficult to control, and challenging to scale up.